Risultati per: Nuovo algoritmo identifica le alterazioni del DNA coinvolte nei tumori

Master in Molecular Pathology and Molecular Tumor Board

In this Viewpoint, 2024 Albert Lasker Basic Medical Research Award winner Zhijian J. Chen describes his discovery of cyclic guanosine monophosphate–adenosine monophosphate synthase (cGAS), a DNA-sensing enzyme that triggers inflammation.

Da Torino l’annuncio di un passo avanti nella lotta al cancro

Le donne possono partecipare inviando un campione biologico

Oncologi, ‘subito un piano di recupero per la prevenzione’

In 30 anni aiutate 900 famiglie con 388mila giorni accoglienza

Le nuove prestazioni erano attese da quasi otto anni e cioè da quando era comparsa la prima versione del tariffario poi sempre rinviato per il nodo risorse

In California una sperimentazione clinica contro una forma considerata letale. Per uno scomparsa la massa

Circulation, Volume 150, Issue Suppl_1, Page A4146311-A4146311, November 12, 2024. Introduction/Background:A 58-year-old man with inotrope dependent heart failure was declined for allotransplant and MCS at multiple centers and was transplanted with a 10 gene-edited porcine cardiac xenograft under FDA expanded access Investigational New Drug (eIND) approval. After requiring perioperative transfusions, by post operative day (POD) 13, endomyocardial biopsy revealed antibody and complement deposition without damage or cellular infiltrate. Hemodynamic decompensation on POD 29 prompted biopsy revealing antibody mediated rejection (AMR). The patient required ECMO support POD31 and chose comfort care POD 40.Research Questions/Hypothesis:The cardiac xenograft doubled in mass from implant to autopsy. Donor derived cell free DNA (cfDNA) correlated temporally with the rejection findings. These processes are hypothesized to correlate.Approach:Routine TTE measurements of diastolic LV posterior wall dimension (LVPWd), intraventricular septal dimension (IVSd), LV mass, and LV mass index were taken. Donor derived cfDNA was measured weekly and PRN (Care Dx Inc., Brisbane, CA). Pearson correlation coefficient analysis was conducted in GraphPad Prism 10 (Dotmatics, Boston, MA).Results/Data:POD 26 TTE measurements indicated thickening graft. POD 30 cfDNA began elevating. cfDNA correlated moderately with LVPWd (r = 0.43, p=0.4) and IVSd (r= 0.5, p=0.31) less so with LV mass (r= 0.28, p=0.59) and LV mass index (r=0.34, p=0.51)Conclusions:Xenograft cardiac thickening measured on TTE preceded elevation in cfDNA. Both were moderately correlated and temporally corresponded to biopsy diagnosed AMR and ultimate graft failure. Future xenograft surveillance will likely benefit from multimodal approach.

Circulation, Volume 150, Issue Suppl_1, Page A4144583-A4144583, November 12, 2024. Donor-derived cell-free DNA (dd-cfDNA) has been increasingly used to detect acute rejection (AR). We aimed to compare our institutional dd-cfDNA results to previously published adult and pediatric dd-cfDNA AR cutoffs. We also hypothesized that in the absence of AR, elevated dd-cfDNA would be associated with CAV and positive DSA.Patients (pt) < 18 years at transplant with >1 dd-cfDNA between 2021-2023 were included. Using dd-cfDNA levels from this cohort, sensitivity, specificity, NPV, and PPV were calculated. False positives and false negatives (FN) were determined using published dd-cfDNA thresholds. AR was defined as decision-to-treat with increased immunosuppression, which was independent of dd-cfDNA in our cohort. In pt without AR,t-test was used to compare the means of dd-cfDNA levels in pt with and without DSA. χ2testing was then performed to evaluate the association between dd-cfDNA levels above and below 0.2% and the presence/absence of DSA and CAV. DSA was defined as allele-specific DSA identified by single antigen bead with mean fluorescence intensity >1000, and CAV as any disease by angiography.There were 379 samples among 163 pt, a median of 2 samples per pt, and 32 samples obtained at time of AR. Performance of dd-cfDNA in our cohort vs published dd-cfDNA thresholds is shown in Table 1. The FN rate ranged from 16 to 37% as the dd-cfDNA threshold increased. Mean dd-cfDNA was higher in patients with positive DSA versus those without (0.83% vs 0.19%, p0.2% were associated with a higher prevalence of positive DSA (n=66) (48% vs 13%, p

Circulation, Volume 150, Issue Suppl_1, Page A4132149-A4132149, November 12, 2024. Background:Heart failure (HF) with reduced ejection fraction (HFrEF) is associated with increased inflammatory response that contributes to progressive worsening of the HF state. Potential endogenous triggers of this process include damage-associated molecular patterns (DAMPs). DAMPs originate from within cells following tissue stress or injury and activate pattern recognition receptors of the immune system, triggering an inflammatory response. Mitochondria are the major cell organelles that release DAMPs into the circulation. Chronic HF is associated with multi-organ mitochondrial dysfunction and cell injury and death.Purpose:The present study sought to quantify differences in mitochondrial DNA (mtDNA) DAMPs in the setting of HFrEF in humans and dogs compared to normal humans and dogs.Methods:Plasma samples were obtained from 9 HFrEF patients with left ventricular ejection fraction (LVEF) ≤35% and 9 age-matched healthy subjects, and from 6 dogs with coronary microembolization-induced HF (LVEF ≤35%) and 6 normal dogs. DNA fragments were isolated from 1 ml of plasma using a commercially available kit. Quantitative PCR and specifically designed primers were used to measure the amount of DNA in plasma fromCOX1(cytochrome c oxidase subunit 1),ND1(NADH dehydrogenase subunit 1) andND6(NADH dehydrogenase subunit 6) using an Applied Biosystems 7500 Fast-PCR unit. The relative abundances of plasma mtDNA DAMPs were expressed as threshold cycles (CT).Results:Compared to normal human subjects, mtDNA DAMPs levels ofCOX1,ND1andND6in plasma of HFrEF patients was 4-fold, 9-fold and 8-fold greater, respectively. Similarly, compared to normal dogs, mtDNA DAMPs levels ofCOX1,ND1andND6in plasma of HFrEF dogs was increased 48-fold, 12-fold and 4-fold, respectively.Conclusions:These findings indicate a marked increase of mtDNA DAMPs in plasma of humans and dogs with HFrEF. The increase of mtDNA DAMPs is consistent with the elevated systemic inflammatory state of HFrEF. The results underscore mitochondrial abnormalities as integral players in the progressive worsening of HFrEF.

Circulation, Volume 150, Issue Suppl_1, Page A4145247-A4145247, November 12, 2024. Background:Plasma donor-derived cell-free DNA (dd-cfDNA) has emerged as a biomarker for acute heart transplant rejection as a potential adjunct to endomyocardial biopsy (EMBx). However, an established threshold for dd-cfDNA in acute cardiac transplant rejection is lacking, with prior studies employing different study specific thresholds. This meta-analysis aims to assess the overall diagnostic accuracy of dd-cfDNA across various cutoffs and provide an optimal threshold.Method:PubMed and Web of Science were searched for relevant publications reporting on the use of dd-cfDNA for the detection of acute cardiac transplant rejection defined as acute cellular rejection (ACR) and/or antibody-mediated rejection (AMR), with EMBx as the reference standard. Pooled sensitivity and specificity were estimated across different thresholds of dd-cfDNA across studies. The optimal dd-cfDNA threshold was estimated by specificity and 1-sensitivity in each data point pooled with fractional polynomial models, maximizing the Youden index between these models.Results:Out of 247 screened papers, 13 studies were included, comprising 12,017 samples from 3,723 patients. Twelve studies used both ACR and AMR and one study used only ACR for the definition of transplant rejection. The thresholds of dd-cfDNA varied across studies, ranging from 0.1 to 0.35 (Figure A). The overall pooled sensitivity and specificity for detecting acute transplant rejection were 0.68 (95% CI: 0.58-0.77) and 0.82 (95% CI: 0.74-0.88) respectively. The areas under the hierarchical modeling-based summary receiver-operating characteristics (sROC) curves were 0.82 (95% CI: 0.78-0.85). Specificity increased with higher thresholds while sensitivity decreased (Figure A and B). The optimal dd-cfDNA threshold derived from combining all included studies was 0.218.Conclusion:Dd-cfDNA assay demonstrates high diagnostic accuracy for acute cardiac transplant rejection, particularly notable for its high specificity. However, there exists significant inconsistency in dd-cfDNA thresholds across studies. Increasing the threshold leads to a trade-off between increased specificity and decreased sensitivity. A cutoff of 0.22 may be considered for dd-cfDNA screening for heart transplant rejection.

Circulation, Volume 150, Issue Suppl_1, Page A4147025-A4147025, November 12, 2024. Heart failure (HF) treatment advances have improved outcomes but HF heterogeneity leads to ~50% response to standard therapies, emphasizing a need to further study mechanisms of disparate outcomes. One serious disparity is increased cardiovascular disease risk and mortality in African Americans (AA) compared to Caucasian Americans (CA). Race is a social construct and thus poor proxy for physiology; hence, our lab studies epigenetics, stable yet reversible changes to DNA serving as a possible interface of how environment impacts gene regulation. We’ve previously implicated cardiac DNA methylation as a new indicator of socio-economic disparities in HF outcomes. Related to HF, US adult obesity rates are 40% and similar disparities exist with AA having higher rates, and studies on obesity show how inequity leads to disparate rates. Thus, our secondary analysis investigates the role of obesity, through its impact on cardiac epigenetics and transcription, as an underlying environment/molecular driver within HF disparities.Multi-omics data of left ventricular assist device placement biopsies of age-matched males were from our previous publication’s public dataset. Cardiac DNA methylation (850k-array) analyzed via minfi, and differential gene expression (RNA-seq) via DESeq2.Two-year survival is decreased in non-obese (NO) vs. obese (OB) patients (p

Circulation, Volume 150, Issue Suppl_1, Page A4143940-A4143940, November 12, 2024. Introduction:Ischemia/reperfusion (I/R) injury occurs after coronary revascularization, contributing to infarct size. Circulating mitochondrial DNA (mtDNA) levels are elevated in acute myocardial infarction (MI) patients, and act as Damage Associated Molecular Patterns (mtDNA DAMP), which are recognized by the Toll-like receptor 9 (TLR9), initiating pro-inflammatory responses. Prior studies have shown that loss of TLR9 prevents I/R injury in isolated mouse hearts. However, mtDNA DAMP levels have not been measured in ST-elevation MI (STEMI) patients, and whether blocking TLR9 in mice can reduce I/R injury remains unknown.Hypothesis:MtDNA DAMP levels serve as markers of STEMI related cardiac injury. Blocking the activation of TLR9 will decrease cardiac I/R injury.Methods:MtDNA DAMP levels in serum were measured pre- and 24 hours post- PCI in 55 STEMI patients and 37 healthy controls by qPCR. To evaluate the role of TLR9 on I/R injury, ODN2088 was used to block TLR9 receptor, wild type and TLR9 germline KO mice were subjected to close-chest I/R surgery with minimal systemic inflammation. The cardiac systolic function and infarct size were assessed. Immune cells were isolated from the injured left ventricle and spleens and detected by flow cytometry.Results:Pre- PCI mtDNA DAMP levels were increased ~200 folds in STEMI patients compared to healthy controls. After PCI, the elevated mtDNA DAMP levels reduced significantly, while the troponin T levels increased, suggesting mtDNA is an early marker of MI. Compared with negative ODN, ODN2088 treatment at reperfusion reduced infarct size and total leukocytes, myeloid cells, neutrophils and TNF-α+cells, and a trend of reduced IL-1β+cells, and there was no difference in IL-6+cells, total macrophages and residential macrophages. Loss of TLR9 in male and female mice significantly reduced infarct size by ~40% and preserved the systolic function. Meanwhile, there is no difference between genders.Conclusions:Circulating mtDNA DAMP level is an early marker of STEMI and may predict the success of PCI. Blocking the mtDNA DAMP-TLR9 signaling pathway during reperfusion significantly reduces I/R injury, indicating it is a viable therapy to mitigate cardiac I/R injury after prompt coronary revascularization.